AN8004

AN8004 is a low cost, single output, linear, adjustable voltage regulator. Owning to its low Quiescent Current, low dropout voltage, excellent line and load Regulation, high output accuracy and output current capability, it is widely used in many applications as a low dropout regulator, battery charger, current limiter and voltage regulator.

1. Applications

The AN8004 linear regulator offer a wide range of applications in board level and embedded system design in computing, communication, consumer and industrial electronics and the Internet of Things (IoT), including but not limited to the following applications:

• Portable Electronic Devices: Mobile phones, notebook computers, hard disk drives, portable media players, digital cameras, etc.
• Vehicle Electronics: Automotive of all kinds, electric bicycles and electric skateboards, etc.
• Home/Office/Medical Electronics: Office machines, white-goods, medical appliances, etc.
• Communication System: Routers, switches, base stations, etc
• Industrial/Other: HVAC, industrial automation, monitoring, etc.

2. Features

AN8004 feature low Quiescent Current; excellent Output Voltage Accuracy and Regulation; high operating Input Voltage range; fast Transient Response; small package size; and advanced protection capabilities, making it ideal for Battery Powered and Portable Electronics Applications.

• High Output Voltage Accuracy: ±0.5%
• High Operating Input Voltage Range: 1.7V-20V
• Low Dropout Voltage, Low Quiescent Current:typmax1.3V, typ.10uA
• High Ripple Rejection: typ.70dB
• Protection Features: Over-Voltage, Over-Current, Thermal Shutdown
• Efficiency: typ.90%

3. Working Principle

AN8004 is a linear regulator which applies the resistive feedback control circuitry to maintain a stable voltage output by detecting the difference between input voltage and output voltage. Such a difference can be either due to output current or variation in the input voltage. It works in the following steps:

• Step 1: When connected to the power supply, the voltage divider configures the reference voltage to set the output voltage.
• Step 2: Detect the difference between the reference voltage and the output voltage.
• Step 3: The voltage error amplifier circuit compares the two voltages and amplifies the difference.
• Step 4: The error amplifier then drives the pass transistor, adjusting the output voltage to match the reference voltage.
• Step 5: The resistor divider configures the reference voltage, output voltage and adjusts the range.

The AN8004 is designed to provide stable output voltage to the load even when there is large input voltage and load variations. It also features protection features such as over-voltage protection, over-current protection and thermal shutdown. The ample output current capability makes it ideal for applications that require high output current.